Numerous innovations for door knob assemblies have been provided in the prior art that are described as follows. Even though these innovations may be suitable for the specific individual purposes to which they address, they differ from the present invention as hereinafter contrasted.
In U.S. Pat. No. 4,639,026, titled Door Knob and Door Knob Catch Arrangement, invented by Jon M. Smallegan, a standard, door knob-operated, latch mechanism is described in which the cylindrical shank of the door knob is slidably engaged with the rotatable spindle of the mechanism, and the spindle has a spring-biased catch projecting therethrough which passes into a slot formed in the cylindrical shank of the knob. In this way, the knob is secured on the shank. The improvement comprises forming a ramp in a cut-out on the terminal or outermost end of the cylindrical shank, and forming a complimentary bevel on a corner of the projecting catch. Accordingly, when the knob is slidably forced onto its spindle, during manufacturing assembly, the ramp formed in the cut-out engages the bevel and, consequently, depresses the catch to allow the cylindrical shank to slide thereupon and thereover, and to allow the catch latchingly to engage the slot.
In U.S. Pat. No. 4,639,021, titled Door Lock, invented by Jimmie L. Hope, a door lock is described for use particularly with sliding patio doors. The lock assembly includes a rotary actuator (door knob) connected to a shaft which drives a crank connected, in turn, to one or more spring-biased bolt rods and operable through the crank to shift the bolt rod to its spring-biased, door-locking position. Stops are positioned to stop the movement of the crank in the locking and unlocking positions of the bolt rod, respectively. Rotary interengaging means such as a pair of meshing gears releasably connect the crank to the shaft assembly. A latch maintains the spring-biased bolt rod releasably in its door-locking position when the gears are meshed. A trip disengages the gear when the bolt rod is in its spring-biased, door-locking position, thereby actuating automatic unlocking of the door.
In U.S. Pat. No. 4,575,137, titled Latch Mechanism and Locking Adaptor, invented by Franz W. Jans, a door latch mechanism is described which includes a housing having a bolt extending outwardly therefrom, and a split sleeve extending through the housing and disposed to drive adjacent cams concentric with the sleeve to operate a retractor to retract the bolt against a biasing spring. The split sleeve receives a split spindle of a door knob assembly to rotate the sleeve and retract the bolt. A locking adapter includes a generally cylindrical housing having a chordal slot for receiving the latch housing therethrough. The cylindrical housing includes aligned apertures through which the spindle extends. A locking cam is secured in one aperture, and a lock release cam is secured in the other aperture. A lock shaft extends through the housing parallel to the axis of the apertures, and includes a boss for engaging and blocking the locking cam to lock the spindle, and a protrusion engagable by the release cam to drive the lock shaft axially to release engagement of the boss and the locking cam. The adapter is joinable to the latch housing to permit locking of the latch mechanism from either side thereof, and the lock is released by rotation of the knob on the locking side.
In U.S. Pat. No. 3,933,014, titled Door Lock Attachment, invented by Adolph Moses, a device is described which is a cheap, one piece, pocketable, one hand operated, snap on or off clamping attachment for a lock bolt thumb knob for preventing the lock from being opened from the outside. One end of the attachment has connected elements that can embrace the thumb knob in either its vertical or horizontal position. The connected elements have two extended legs that spring grip the door knob hub and can bias the attachment to its operative position or hold it in its inoperative position. This cheap device takes the place of a more expensive bolt and its installation cost.
The above patented inventions differ from the present invention because they fail to describe or claim at least one combination of the following features depicted in the present invention.